Question
The ratio of the speed of boats ‘A’ and ‘B’ in still water is 8:9, respectively. The speed of the current is 25% of the speed of boat ‘A’ in still water. If boat ‘A’ takes 10 hours to travel 500 km downstream, then find the time taken by boat ‘B’ to travel 70 km upstream and 275 km downstream. (Note: Both the boats are rowing in the same stream.)
Solution
Let the speeds of boats ‘A’ and ‘B’ in still water be 8x km/hr and 9x km/hr Therefore, speed of the current = 0.25 × 8x = 2x km/hr According to the question, 8x + 2x = 500/10 Or, 10x = 50 Or, x = 5 Therefore, upstream speed of boat ‘B’ = 9x – 2x = 7x = 35 km/hr Downstream speed of boat ‘B’ = 9x + 2x = 11x = 55 km/hr Required time taken = (70/35) + (275/55) = 2 + 5 = 7 hours
More Boats and streams Questions
- If a man rows at the rate of 14 kmph in still water and his rate against the current is 5 kmph, then the man’s rate along the current is:  ...
- A boat sailor begins rowing from point X, moving against the stream for 30 minutes. After that, he turns around and rows with the stream for another 30 min...
- Speed of a boat in still water to speed of boat in upstream is 7:4. If the boat can travel 450 km in downstream in 5 hours, then find the time taken by the...
- A man swims downstream 49 km and upstream 35 km, taking 7 hr each time. What is the velocity of current?
- A boy can swim in water with a speed of 12 km/hr in still water. If the speed of the stream is 6 km/hr, what will be the time taken by the boy to cover 72 ...
- Determine the speed of a Ship in calm water, given that the Ship's speed downstream is 20% greater than its speed in still water. If the Ship can cover 48 ...
- A boat can cover 36 km in still water and 45 km in downstream in 4 hours and 3 hours respectively. Find the time taken by the boat to cover 60 km upstream ...
- A boat takes 6 hours to cover 288 km downstream and 7 hours to cover 168 km upstream. Find the time taken by the boat to cover 180 km in still water.
- Speed of a boat in still water to speed of boat in upstream is 10:7. If the boat can travel 390 km in downstream in 5 hours, then find the time taken by th...
- The speed of a boat is that of the current of water is 40:3. The boat goes along with the current in 3 hours 8 minutes. It will come back in
